1. Technical Field
The invention relates to a three-phase permanent magnet type motor including a multilayer wiring board that connects windings of a motor in which the number of slots is equal to an integer multiple of 12, and the number of poles is equal to an integer multiple of 10 or an integer multiple of 14.
2. Description of Related Arts
In the prior art, a two parallel connection of a three-phase permanent magnet type motor with 10 or 14 poles and 12 slots has been performed using multilayer printed wiring boards of five layers or more. When using the multilayer printed wiring boards of the five layers or more, there has been a problem in that a manufacturing cost increases.
Furthermore, the conventional two parallel connection structure has problems in that an electromagnetic force acting as a factor causing a rotor eccentricity due to imbalance of a winding impedance increases, and a torque ripple acting as a factor causing the speed fluctuation increases.
Therefore, in order to reduce the rotor eccentric force and the speed fluctuation, multilayer printed wiring boards of the series connection have been used.
For example, a three-phase magnet motor with 10 poles and 12 slots has been suggested that is connected via a wiring pattern formed on the multilayer of the multilayer printed wiring board so that current directions of adjacent in-phase windings are facing directions, current directions of adjacent out-of-phase windings are the same direction, and two circuits formed by connecting the adjacent in-phase windings in series are connected in parallel (see Japanese Patent No. 4670868).
However, according to the technique of Japanese Patent No. 4670868, an electric wire diameter of the winding becomes thicker than that of a case of the two parallel connection, a space factor of the winding is lowered, and the motor efficiency is lowered.
As a technique for solving this problem, for example, a winding-connection technique has been suggested in which adjacent in-phase windings are connected in parallel and are connected to a facing symmetrical in-phase winding in series, and a series winding circuit is formed by one line (see, Japanese Patent Application Laid-Open Publication No. 2010-193675).
Incidentally, according to the technique of Japanese Patent Application Laid-Open Publication No. 2010-193675, it is possible to reduce the electromagnetic force that is a factor of the rotor eccentricity, and the torque ripple that is a factor of the speed fluctuation, and it is possible to reduce the multilayer printed wiring board having five layers or more in the prior art to four layers.
However, according to the technique of Japanese Patent Application Laid-Open Publication No. 2010-193675, the workability is likely to worsen, and the manufacturing cost of the multilayer wiring board increases.
The present invention has been devised in view of the above circumstances, and an object thereof is to provide a three-phase permanent magnet type motor that is capable of reducing the electromagnetic force that is a factor of the rotor eccentricity, and the torque ripple which is a factor of the speed fluctuation, reducing the number of layers of the multilayer wiring board forming a connection pattern of the winding, and reducing the manufacturing cost of the multilayer wiring board.